Currently, a printer is used in financial institutions for printing images on a booklet such as a bankbook and a ledger sheet such as a bank statement. Typically, a dot printer is used to print images on the booklet. The booklet is inserted into the dot printer by a user and printing is performed thereon. On the other hand, a thermal printer is typically used to print the ledger sheet, and a sheet stored in the thermal printer is used to print the ledger sheet. One type of a printer has both a dot printing unit and a thermal printing unit, and has a single sheet conveyance path that is shared by the dot printing unit and the thermal printing unit to make the printer smaller.
However, as the single sheet conveyance path is used, one of the printing units cannot perform printing while the other one of the printing units performs printing. One solution to avoid such a conflict between the two printing units is controlling the timing of printing by an external device. However, with this solution, when there is a modification of the print settings or replacement of the printing units, the timing of printing may need to be adjusted and the external device needs to be reprogrammed accordingly.